This is the flip side of the "self-made man" narrative.

It allows one to disavow any sense of social reciprocity after becoming obscenely rich.

I was curious, so I looked through his Wikipedia page -- it says he donated $1m to the Hebrew Immigrant Aid Society in 2009 (which helped his family move to USA when he was a child). Even the NYT article notes that "The gift is small, given Mr. Brin’s estimated $16 billion in personal wealth" :D

(this is like you making $1m annually and donating $62.50)